Chronologically by game release, this is how the story goes, IGA games are not included.
(Super) Castlevania (Chronicles) - Simon Defeats Dracula
-Dracula Places Curse on Simon-
Castlevania 2 - Simon Ressurects Dracula himself and Defeats him again to break the Curse.
Castlevania The Adventure - Christopher Strikes Down Dracula
Castlevaina 3 - Goes back to how the Legend Began, Introduces multiple characters and how the Belmont clan became famous by Trevor's Doing
Castlevania 2 Belmont's Revenge - Dracula has Christopher's Son, He Defeats Dracula to reunited with his son.
Dracula X(X)- Richter Takes up the Duty and Saves a few people along the Way.
Castlevania Bloodlines - Links the Castlevania Canon with the Bram Stoker's Canon.
Castlevania Legends - Introduces a Female Belmont, also adds a Twist in the Plot involving Alucard being Trevor's Father.
Castlevania 64/LoD - Pretty Much self Contained Story, no need to reference it.
Conflicts in Story with IGA games
SoTN - Shaft was Killed along with his ghost in Dracula X, Plus Simon had Already Willingly Ressurected Dracula so turning Richter Evil was unnecessary. Also the entire shaft part was meaningless as Alucard Pretty much Ressurected Dracula himself a-la Castlevania 2
Synopsis - This is probably the 32x game's plot as the rival wanted to ressurect Dracula, but they changed him to Richter, along with a bunch of other changes, Can't explain shaft though...
CoTM - No Conflicts here.
HoD - No Conflict.
Aria of Sorrow - No Conflicts.
Lament of innocence - Conflicts with just about every Castlevania game. Dracula was Already set up to be Vlad III/Bram Stoker's Dracula, The Belmont's were unrelated to Dracula in any way until Castlevania 3 / Legends, For a Story that Center's around Dracula, the LAST thing to do is FUCK UP THE MYTHOS.
Synopsis - this is later to recent IGA, he's pretty much forcing his own Story to the timeline, it would have been much better just to Consider it a reboot.
Dawn of Sorrow - Convenient Sequel plot is stupid, If there were more Dark lord candidates hey would have respectively showed up in AoS to Battle for the Throne, Soma Killed off the source of the Castle's power, thus ending Castlevania itself, Also this takes place 1 year after Aria, why is Julius that weak?
Synopsis - This plot is solely just to make a sequel and not much thought went into it, With no Dracula and no Castlevania in the plot, this is pretty much a Vain title.
Curse of Darkness - First off, Dracula had no problem spawning minions even before his resurrection in EVERY game before it, With Devil Forgers who Forge NOTHING that remotely resembles anything from Castlevania 3, I find this entire plot Really Stupid, Plus, where is Sypha and Grant? if your gonna mention them, dammit give em screen time!
Synopsis- Just a lame excuse to make a game to feature Trevor Belmont, and Force feed the 1999 prediction Crap too, IGA is Just Cheesing by now.
Portrait of Ruin - adding needless crap is now the way to go, Now bloodlines Serves no Purpose since there is no bram Stoker connection, The Morris Family is part of the Belmont Clan, Eric Looks NOTHING, NOTHING! like his original self, Dracula is the Lord of Darkness and The highest of all Vampires yet Brauner Traps him in the throne Room.
Yet again more force feeding on the 1999 Crap adding that the Vampire killer has to be unlocked but can't be as strong as a Belmont Wielding it, YET JOHN GETS HOLY LIGHTNING 4TH UPGRADE WHICH 1HKs EVERYTHING!
Synopsis - I know IGA has never played half of the games he makes sequels to now, this is a Frikken Uwe Boll move.
Order Of Ecclesia - No Conflict? What?
Synopsis - This is a Prime Example where IGA can be Very Good, I Wish He could Just do this for all his games.